I just learned about a method of machining that I had never even heard of before, Wire EDM (Electrical Discharge Machining). The machine uses a very thin wire with a high voltage to spark erode any conductive metal with amazing precision . These machines can cut a .001 inch line through up to 20 inches of any conductive metal. It seems to cut at the same feed rate regardless of the thickness of the part.
Amazing technology, I wonder how long before some builds a hobby EDM machine?
We use one here at work, mostly for cutting either extremely high-precision shapes (greater than our mills can make, which is rare) or for cutting things that clamping in the mill would be impractical (conductor pins, bifurcations, etc). It makes an absolutely beautiful cut, but is incredibly slow!
I’d guess it will be quite a while, given how long EDM has been around as an industrial technique. xD The oil bath and power requirements make it a bit impractical for the home shop.
How much power does a machine like that require?
I really am not sure, but the mains supply lines going into the sucker are the equal of the ones going into our big mills. And ours is only a medium-sized unit. I can’t imagine it’d be less than a fairly heavy MIG unit or something similar…
As I just google around a bit, it seems that I might be wrong, some people HAVE been rigging their own shop-scale EDM stuff? Woah.
EDIT: Ours uses some kind of non-flamable dielectric oil as the bath.
The one I was looking at seemed to use a deionized water bath.
So not a new kind of Electronic Dance Music? (EDM)
There are DIY EDM mahcines (seems just a little bit scary). This one runs off of 100VDC
As I understand, it just has to be an insulating fluid to allow the potential to build up before it breaks down to generate the erosive sparks.
Doing a little more reading I see that the machine does not need to use a wire, any suitable electrode will work, so you can use a square shaped electrode to “cut” a square keyway into the side of a shaft.
The simple version of the machine is mostly the power supply and the control system.
Correct, that is a “sinker” EDM as opposed to a “wire” EDM. We have one of those as well, although it’s older than I am, and very rarely used.
For a Hobby machine the “sinker” type seems much simpler to build and use.
I really need a machine with about 40 analog control knobs and switches on the front panel !
It seems like with this technology could use an infusion of digital technology.
Check out https://www.youtube.com/watch?v=EeKreZqgi9M for an EDM project. This is a great YouTube channel - really entertaining and incidental learning.
I find him very offensive. Why does he think every one wants to hear him use the F word every other sentence.
Just saw this video showing how precise a cut the wire EDM can make is thick steel. basically a seamless interface between the two parts
I would love to find some place that sells this demo